Question: Simplify the following expression: $x = \dfrac{7r}{8} + \dfrac{r}{2}$
Explanation: In order to add expressions, they must have a common denominator. The smallest common denominator is the least common multiple of $8$ and $2$ $\lcm(8, 2) = 8$ $ x = \dfrac{1}{1} \cdot \dfrac{7r}{8} + \dfrac{4}{4} \cdot \dfrac{r}{2} $ $x = \dfrac{7r}{8} + \dfrac{4r}{8}$ $x = \dfrac{7r +4r}{8}$ $x = \dfrac{11r}{8}$